Solve the equation: [3255] [x1 x2] + [1 2] = [2 -3]

About 2% of the population has a particular genetic mutation. 400 people are randomly selected. Find the mean for the number of

sergeinik [125]

Answer:

200

Step-by-step explanation:

So it'll be 400 ÷ 2 = 200 , and a way to to check your way would be 200 x 2 = 400

5 0

3 years ago

Four graphs are shown below:

vaieri [72.5K]

Graph b would be my guess!

5 0

3 years ago

A geologist has collected 5 specimens of basaltic rock and 7 specimens of granite. The geologist instructs a laboratory assistan

MaRussiya [10]

The rocks are chosen without replacement, which means that the hypergeometric distribution is used to solve this question. First we get the parameters, and then we answer the questions. From this, we get that:

$E(X) = 5.25, Var(X) = 0.5966$
P(X < 6) = 0.9545
P(all specimens of one of the two types of rock are selected for analysis) = 0.2046.

Hypergeometric distribution:

The probability of x successes is given by the following formula:

$P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}$

In which:

x is the number of successes.

N is the size of the population.

n is the size of the sample.

k is the total number of desired outcomes.

Combinations formula:

$C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

The mean and the variance are:

$\mu = \frac{nk}{N}$

$\sigma^2 = \frac{nk(N-k)(N-n)}{N^2(N-1)}$

We have that:

5 + 7 = 12 rocks, which means that $N = 12$

9 are chosen, which means that $n = 9$

7 are granite, which means that $k = 7$

Question a:

$E(X) = \mu = \frac{9\times7}{12} = 5.25$

$Var(X) = \sigma^2 = \frac{9\times7(12-7)(12-9)}{12^2(12-1)} = 0.5966$

Thus:

$E(X) = 5.25, Var(X) = 0.5966$

Question b:

Since there are only 5 specimens of basaltic rock, at least 9 - 5 = 4 specimens of granite are needed, which means that:

$P(X < 6) = P(X = 4) + P(X = 5) + P(X = 6)$

In which

$P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}$

$P(X = 4) = h(4,12,9,7) = \frac{C_{7,4}*C_{5,5}}{C_{12,9}} = 0.1591$

$P(X = 5) = h(5,12,9,7) = \frac{C_{7,5}*C_{5,4}}{C_{12,9}} = 0.4773$

$P(X = 6) = h(6,12,9,7) = \frac{C_{7,6}*C_{5,3}}{C_{12,9}} = 0.3181$

Thus

$P(X < 6) = P(X = 4) + P(X = 5) + P(X = 6) = 0.1591 + 0.4773 + 0.3181 = 0.9545$

So P(X < 6) = 0.9545.

Question c:

5 of basaltic and 4 of granite: 0.1591 probability.

7 of granite is P(X = 7), in which

$P(X = 7) = h(7,12,9,7) = \frac{C_{7,7}*C_{5,2}}{C_{12,9}} = 0.0455$

0.1591 + 0.0455 = 0.2046, thus:

P(all specimens of one of the two types of rock are selected for analysis) = 0.2046.

A similar question is found at brainly.com/question/24008577

5 0

3 years ago

ABM Services paid a $4.15 annual dividend on a day it closed at a price of $54 per share. What

n200080 [17]

Answer:

the yield is 7.68%

Step-by-step explanation:

The calculation of the yield is given below:

we know that

Yield is

= Annual dividend ÷ Price per share

= $4.15 ÷ $54

= 7.68%

Here we divide the annual dividend by the price per share in order to determine the yield

hence, the yield is 7.68%

And, the same would be considered

6 0

3 years ago

Your cousin is taking the train to Washington to visit her parents. She has at most $15.00 to spend on snacks and reading materi

erma4kov [3.2K]

I think 6 of each. I divided 15 by 2, got $7.50. You can buy exactly six magazines w that, and 6.5 granola bars. So six of each.

8 0

3 years ago

Solve the equation: [3255] [x1 x2] + [1 2] = [2 -3]​

Solve the equation: [3255] [x1 x2] + [1 2] = [2 -3]